Er.....I mean,come on chaps.....£/$30 plus 15% of contract sum, plus 17.5% VAT, plus 15% for UK market....I wasn't really that grateful....in fact I didn't really want to know in the first place.As it happens I knew all ready.
(Retires to search for one's copy of "Debrett's Etiquette"-they must have a chapter or two as to what to do next in this situation")